| 摘要 |
PROBLEM TO BE SOLVED: To avoid problems of an enlarged device and increased cost due to providing a magnetic field source shielding member such as a ferrite plate, and also to reduce problems of degradation in power transmission efficiency and heat generation due to eddy current.SOLUTION: A wireless power transmission device includes a power transmission coil 10 magnetically coupled to a power reception coil of a wireless power reception device, and a power transmission circuit 9 connected to the power transmission coil 10. The power transmission coil 10 includes a first coil 11, a second coil 12 and a third coil 13 which have winding axes that are coaxial with each other and coil openings of a substantially equal size. The second coil 12 is arranged on a wireless power reception device side with the first coil 11 as a reference, and the third coil 13 is arranged to a side opposite to the wireless power reception device side. The power transmission circuit 9 performs phase control of currents conducted to the first coil 11, the second coil 12 and the third coil 13.SELECTED DRAWING: Figure 3 |
